Endoscopic surgical procedures are routinely performed in order to accomplish various surgical tasks. In an endoscopic surgical procedure, small incisions, called portals, are made into the patient. An endoscope, which is a device that allows medical personnel to view the surgical site, is inserted in one of the portals. Surgical instruments used to perform a specific surgical task are inserted into other portals. The surgeon views the surgical site through the endoscope to determine how to manipulate the surgical instruments in order to accomplish the surgical procedure. An advantage of performing endoscopic surgery is that, since the portions of the body that are cut open are minimized, the portions of the body that need to heal after surgery are likewise reduced. Moreover, during an endoscopic surgical procedure, only relatively small portions of the patient's internal organs and tissue are exposed to the open environment. This minimal opening of the patient's body lessens the extent to which a patient's organs and tissue are open to infection.
The ability to perform endoscopic surgery has been enhanced by the development of powered surgical tools especially designed to perform endoscopic surgical procedures. One such tool, for example, is sold by the Applicant's Assignee under the trademark HUMMER TPS. This tool is in the form of a cylindrical handpiece designed to be held in the hand of the surgeon. Internal to the handpiece there is a motor. A front end of the handpiece is provided with a coupling assembly for releasably holding a cutting accessory. The types of cutting accessories that are attached to this handpiece include shavers, resectors, planers and burs. Integral with the motor and coupling assembly is a device for transmitting the rotary power developed by the motor to the cutting accessory.
The handpiece also has a suction conduit. This is because, in an endoscopic surgical procedure, irrigating fluid is introduced into the surgical site. This fluid serves as a transport media for removing debris from the surgical site. In order to remove the irrigating fluid, and the material in the fluid, a suction path is provided through the cutting accessory and the handpiece. A suction pump is connected to the handpiece and provides a suction force for drawing the fluid and material away from the surgical site. In order to control the suction flow through the cutting accessory and the handpiece, the handpiece is provided with a manually operated valve. Thus, with a single handpiece, a surgeon both manipulates the cutting accessory and controls the suction of material away from the surgical site.
For the above reasons, presently available handpieces have proven to be very useful tools for performing surgical procedures. Nevertheless, there is a limitation associated with the suction systems that are integral with these handpieces. Specifically it is very difficult for a surgeon to regulate the suction rate, the rate at which fluid and debris are drawn away from the surgical site through the handpiece. Presently available handpieces have valves that allow variable control of suction flow through the associated suction conduit.
The Applicant's U.S. patent application Ser. No. 09/454,113, filed Dec. 3, 1999, entitled POWERED SURGICAL HANDPIECE WITH SUCTION CONDUIT INCLUDING A STEPPED VALVE TO REGULATE FLOW THROUGH THE SUCTION CONDUIT, now U.S. Pat. No. 6,436,067 and incorporated herein by reference, discloses one such powered surgical handpiece with a suction valve. The handpiece of this invention includes a valve with an indexing mechanism that provides tactile feedback when the valve is in an intermediate position between its fully open and fully closed states. This handpiece thus provides a surgeon with some ability to sense the position of the suction control valve when it is between its fully open and fully closed states.
Nevertheless, there are some limitations associated with the suction control offered by available handpieces. One limitation is associated with available handpieces is that it is often difficult to set the associated valve to a position in which the valve only allows a relatively small suction to be drawn at the surgical site.
Still another disadvantage of many handpieces is that even when their suction valves are in the fully closed states, there may be some leakage suction flow. Sometimes a surgeon finds the presence of this flow distracting.
Furthermore, handpieces are typically designed so that the suction flow out of the handpiece is through a tube that is attached to the proximal end, the rear end, of the handpiece. Sometimes, if a surgeon holds the handpiece in an unusual position, this tube may bend or fold over itself. If either of these two events occur, the tube may close and, in effect, stop further suction flow from the surgical site. If this flow is blocked, the surgeon must take the time to interrupt the procedure to remove the bend in the tube so as to allow suction flow to continue. Making the surgeon perform this task interrupts his/her concentration from the actual surgical procedure and lengthens the overall time it takes to perform the procedure. The lengthening the time it takes to perform a surgical procedure runs contrary to one of the goals of modern surgical practice which is to hold the time the patient is kept under anesthesia to as short as possible.
Also, even if the tube does not fold shut, if the handpiece to which it is attached is held in an unusual position, the tube may drag across the arms or other body parts of the surgeon. This contact with the tube may interfere with the surgeon's ability to perform the desired surgical procedure or simply distract the surgeon's attention.